APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

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APOD Robot
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APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by APOD Robot » Tue Mar 06, 2018 5:06 am

Image Colorful Airglow Bands Surround Milky Way

Explanation: Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere. These gravity waves are oscillations in air analogous to those created when a rock is thrown in calm water. Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up. While driving near Keluke Lake in Qinghai Provence in China, the photographer originally noticed mainly the impressive central band of the Milky Way Galaxy. Stopping to photograph it, surprisingly, the resulting sensitive camera image showed airglow bands to be quite prominent and span the entire sky. The featured image has been digitally enhanced to make the colors more vibrant.

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by BDanielMayfield » Tue Mar 06, 2018 5:36 am

Extraordinary, stunning image. Wow.
APOD Robot wrote:
Tue Mar 06, 2018 5:06 am
Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up.
There also appears to be some purple airglow as well. Is it's sorce known?

Bruce
"Happy are the peaceable ... "

Ed Casebier

Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by Ed Casebier » Tue Mar 06, 2018 6:20 am

Gorgeous backdrop from China of a 2017 Buick Envision.

Rodrigo Camargo

Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by Rodrigo Camargo » Tue Mar 06, 2018 10:25 am

Nice picture. Anyone can see M31 and M33!!!

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by neufer » Tue Mar 06, 2018 12:56 pm

BDanielMayfield wrote:
Tue Mar 06, 2018 5:36 am
APOD Robot wrote:
Tue Mar 06, 2018 5:06 am

Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up.
There also appears to be some purple airglow as well. Is it's source known?
Based on the spectrum from: https://www.atoptics.co.uk/highsky/airglow2.htm most of
the colors would come from oxygen atoms (with only deep red coming from hydroxyl molecules).
Art Neuendorffer

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orin stepanek
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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by orin stepanek » Tue Mar 06, 2018 1:27 pm

Beautiful; worthy of being a wallpaper! 8-) :D
Orin

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by Zuben L. Genubi » Tue Mar 06, 2018 4:36 pm

Can someone please explain the part about storms causing gravity waves? I thought gravity waves were only recently proven to exist.

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neufer
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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by neufer » Tue Mar 06, 2018 4:50 pm

Zuben L. Genubi wrote:
Tue Mar 06, 2018 4:36 pm

Can someone please explain the part about storms causing gravity waves?
I thought gravity waves were only recently proven to exist.
Gravitational waves (i.e., propagating ripples in spacetime) were only recently observed to exist.

Gravity waves (i.e., propagating disturbances in a fluid caused primarily by gravitational restoring forces)
have been known since humans first observed ocean waves.
Art Neuendorffer

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by ta152h0 » Tue Mar 06, 2018 7:56 pm

So giant Black Holes eat dark matter to get so big so fast ? Getting schooled here big time. Back to admiring today's APOD and having a cup of brew !
Wolf Kotenberg

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by empty_space » Wed Mar 07, 2018 12:59 am

ta152h0 wrote:
Tue Mar 06, 2018 7:56 pm
So giant Black Holes eat dark matter to get so big so fast ? Getting schooled here big time. Back to admiring today's APOD and having a cup of brew !
A brew and the wonders from APOD is the true meaning of life! :)

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Re: APOD: Colorful Airglow Bands Surround Way... (2018 Mar 06)

Post by BDanielMayfield » Wed Mar 07, 2018 6:35 am

neufer wrote:
Tue Mar 06, 2018 12:56 pm
BDanielMayfield wrote:
Tue Mar 06, 2018 5:36 am
APOD Robot wrote:
Tue Mar 06, 2018 5:06 am

Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up.
There also appears to be some purple airglow as well. Is it's source known?
Based on the spectrum from: https://www.atoptics.co.uk/highsky/airglow2.htm most of
the colors would come from oxygen atoms (with only deep red coming from hydroxyl molecules).
Thanks Art. That reference was helpful. From it it appears that the purple color is coming from O2 molecules.

Bruce
"Happy are the peaceable ... "